Not to be confused with other Google Wallet services, like using NFC enabled phone (most Android phones are) for paying at your favorite coffee bar as it is a separate business for Google. Also if you are a developer, to charge your users through in app purchaces. Those will continue to function as they have done before.
"If you are selling apps on the Google Play Store or processing in-app payments through Google Wallet, you will continue to be supported. You will be able to access your Google Wallet Merchant Center as normal at wallet.google.com/merchant."The retirement is if you are using Google Wallet to sell your digital goods, say like on a website. You will need to sign up with another merchant, if you have already done so.
Get more info at Google. Specific info on removing the integration is available at the Google Developer Site. Sphere: Related Content